Videotape of the Navy mission to shoot down a dying spy satellite made available Thursday shows an interceptor missile ascending atop a bright trail of burning fuel, and then a flash, a fireball, a plume of vapor. A cloud of debris left little doubt that the missile had squarely hit its mark as the satellite spent its final days orbiting more than 130 miles above the Pacific Ocean.
A different kind of doubt still lingers, though, expressed by policy analysts, some politicians and scientists, and not a few foreign powers, especially China and Russia:
Should the people of the world be breathing a sigh of relief that the risk of a half-ton of frozen, toxic rocket fuel landing who knows where has passed? Or should they be worried about the latest display of the United States’ technical prowess, and see it as a thinly veiled test for a shadow antisatellite program?
Defense Secretary Robert M. Gates, who personally gave the order to go ahead with the satellite shootdown Wednesday, told reporters in Hawaii on Thursday that he was prepared to share some details of the operation with China to ease its concerns that the debris might still prove dangerous. Adm. Timothy J. Keating, the commander of American forces in the Pacific, has reached out to several nations in the region to explain the mission, as well.
Addressing the diplomatic concerns, senior officials dismissed questions raised by the Chinese and the Russians, and echoed by some arms control analysts, about whether the episode was really a test of space weaponry. They pointed out that the missile used in the operation, the Navy’s SM-3 interceptor, was designed to counter a limited ballistic missile attack and had to be reprogrammed for this unexpected task, the likes of which the authorities are unlikely ever to face again.
In missile defense, an interceptor must find a red-hot enemy warhead as it arcs on a relatively short ballistic path, a task often described as “hitting a bullet with a bullet.” This time, the target — much larger then a warhead, almost the size of a school bus — was circling Earth predictably about 16 times a day.
It was still a bit of a long shot. The fuel tank that was the bull’s eye was only about 40 inches across.
And although the United States has hit test targets in space before — including a satellite destroyed in 1985 in a demonstration of an antisatellite weapon launched from a fighter jet — the successful demonstrations have been relatively few and far between.
What Wednesday’s successful strike in space conclusively proved was not infallibility but a robust and flexible military capability that can be cited by either side in what no doubt will be the ensuing debate.
The mission was conducted from Navy warships. So the United States can move this capability at will over three-quarters of the globe.
The missile-defense interceptor was converted to an antisatellite capability in little more than a month. No expensive research and development program. No battles with Congress over money. No starting from scratch on white boards in some laboratory.
This demonstration of military agility has to cause any adversary to pause.
“This was uncharted territory,” said Gen. James E. Cartwright of the Marines, who is vice chairman of the Joint Chiefs of Staff. “The technical degree of difficulty was significant here.”
General Cartwright noted that important elements of the nation’s missile defense system had been used, in particular the sensors.
“That was the key piece that we would take from the missile defense system,” he said.
To ready the missile-defense rocket for the mission, he said: “We added a lot of instrumentation. We made some modifications to the software to be able to go after a satellite.”
In somewhat theatrical language, the mission was hailed by Riki Ellison, president of the Missile Defense Advocacy Alliance, one of the more energetic groups promoting the development of ballistic missile defenses.
“The factual reality of using deployed missile defenses to destroy a falling satellite or a ballistic missile or even a meteor from space that would risk human life is an achievement for mankind,” a statement from the organization said.
Yet, even the successful mission in no way proves that the United States is safe from nuclear attack, or that it can do what it wants in space.
Mr. Gates, at the start of a weeklong series of meetings in Asia, said that the debate over whether the United States’ missile defense system worked was “behind us” but that issues remained about exactly what types of missile threats the system could be used against.
“The question of whether this capability works has been settled,” Mr. Gates said in Hawaii after a tour of the destroyer Russell, which participated in the satellite operation. “The question is against what kind of threat, how large a threat, how sophisticated a threat.”
The White House and the Pentagon said the hazard posed by the failed National Reconnaissance Office satellite was from its hydrazine fuel. It may be 24 to 48 hours before officials can state with certainty that the fuel tank was punctured and that the hydrazine is no longer a threat.
But Representative Edward J. Markey, a Massachusetts Democrat on the House Homeland Security Committee, said, “The geopolitical fallout of this intercept could be far greater than any chemical fallout that would have resulted from the wayward satellite.”
Mr. Markey said: “The Bush administration’s decision to use a missile to destroy the satellite based on a questionable ‘safety’ justification poses a great danger of signaling an ‘open season’ for other nations to test weapons for use against our satellites. Russia and China are sure to view this intercept as proof that the United States is already pursuing an arms race in space, and that they need to catch up.”
The Chinese warned Thursday that the United States Navy’s action could threaten security in outer space. Liu Jianchao, the Chinese Foreign Ministry spokesman, said at a news conference in Beijing that the United States should promptly share data about the passage of the remaining pieces of the satellite.
“China is continuously following closely the possible harm caused by the U.S. action to outer space security and relevant countries,” Mr. Liu said, according to The Associated Press.
more....
The U.S. is confident that its shooting down of a disabled spy satellite with a missile managed to destroy its potentially toxic fuel tank.
Marine Gen James Cartwright said there was a 80-90% chance that the satellite's tank had been destroyed.
A fire ball, vapor cloud and spectral analysis indicating the presence of hydrazine all indicated that the tank had been hit, he told reporters.
The operation has been criticized by China and Russia. ""We're very confident that we hit the satellite,"" Gen Cartwright said at a Pentagon briefing hours after the missile was fired. ""We also have a high degree of confidence that we got the tank.""
It would take another 24-48 hours for officials to confirm whether the operations had been completely successful, he said.
Gen Cartwright said he could not rule out that hazardous material might fall to earth, but said there was no evidence of this happening so far.
He added that officials would continue to track debris falling over the Atlantic and Pacific Oceans over the next two days. ""Thus far we've seen nothing larger than a football,"" he said.
The satellite, USA 193, was struck 153 nautical miles (283 km) above earth by an SM-3 missile fired from a warship in waters west of Hawaii.
Arms race?
Operatives had only a 10-second window to hit the satellite, which went out of control shortly after it was launched in December 2006.
The missile needed to pierce the bus-sized satellite's fuel tank, containing more than 450kg (1,000lbs) of toxic hydrazine, which was otherwise expected to survive re-entry.
USA 193 lost control shortly after launch on a Delta II rocket China called on the US on Thursday to provide more information about the mission.
Russia suspects the operation was a cover to test anti-satellite technology under the U.S. missile defense program.
The U.S. denies the operation was a response to an anti-satellite test carried out by China last year, which prompted fears of a space arms race.
US officials had said that without an attempt to destroy the fuel tank, and with the satellite's thermal control system gone, the fuel would have been frozen solid, allowing the tank to resist the heat of re-entry.
If the tank were to have landed intact, it could have leaked toxic gas over a wide area - harming or killing humans if inhaled, officials had warned.
""The intent here was to preserve human life ... it was the hydrazine we were after,"" Gen Cartwright said on Thursday.
The U.S. has also denied that it shot down the satellite to prevent parts of it from falling into the hands of foreign powers.
Gen Cartwright said most of the satellite's intelligence value was likely to have been destroyed.
No comments:
Post a Comment